Biology subjects

Keereetaweep, J.

Publications and source records attributed to Keereetaweep, J..

3 recordsLinked to original sources

bioRxiv2022

Interplay between MYZUS PERSICAE-INDUCED LIPASE 1 and OPDA signaling in controlling green peach aphid infestation on Arabidopsis thaliana

MYZUS PERSICAE-INDUCED LIPASE1 (MPL1) encodes a lipase in Arabidopsis thaliana that is required for controlling infestation by the green peach aphid (GPA; Myzus persicae), an important phloem sap-consuming insect pest. Previously, we demonstrated that MPL1 expression was upregulated in response to GPA infestation, and GPA fecundity was higher on the mpl1 mutant, compared to the wild-type (WT), and lower on 35S:MPL1 plants that constitutively expressed MPL1 from the 35S promoter. Here, we show that the MPL1 promoter is active in the phloem and expression of the MPL1 coding sequence from the phloem-specific SUC2 promoter is sufficient to restore resistance to the GPA in the mpl1 mutant. The GPA infestation-associated upregulation of MPL1 requires CYCLOPHILIN 20-3 (CYP20-3), which encodes a 12-oxo- phytodienoic acid (OPDA)-binding protein that is involved in OPDA signaling and is required for controlling GPA infestation. OPDA promotes MPL1 expression to limit GPA fecundity, a process that requires CYP20-3 function. These results along with our observation that constitutive expression of MPL1 from the 35S promoter restores resistance to the GPA in the cyp20-3 mutant, and MPL1 feedbacks to limit OPDA levels in GPA-infested plants, suggest that an interplay between MPL1, OPDA, and CYP20-3 contributes to resistance to the GPA. HighlightInteraction between MYZUS PERSICAE-INDUCED LIPASE 1 function in the phloem, and 12-oxo-phytodienoic acid (OPDA) and CYCLOPHILIN 20-3, which encodes an OPDA-binding protein that is involved in OPDA signaling, is involved in controlling green peach aphid infestation on Arabidopsis thaliana.

plant biology↗

bioRxiv2020

An Expanded Role for WRINKLED1 Metabolic Control Based on Combined Phylogenetic and Biochemical Analyses

During triacylglycerol biosynthesis in developing oilseeds of Arabidopsis thaliana, fatty acid production is regulated by the seed-specific transcription factor WRINKLED1 (WRI1). WRI1 is known to directly stimulate the expression of fatty acid biosynthetic enzymes and a few targets in glycolysis. However, it remains unclear to what extent and how the conversion of sugars into fatty acid biosynthetic precursors in seeds is controlled by WRI1. Based on a previously reported DNA binding motif for WRI1, the ASML1/WRI1 (AW)- box, we developed a comparative genomics approach to search for conserved binding motifs in upstream regions of Arabidopsis thaliana protein-encoding genes and orthologous regions of 11 other Brassicaceae species. The AW-box was over-represented across orthologs for 915 Arabidopsis thaliana genes. Among these, 73 genes with functions in the biosynthesis of fatty acids and triacylglycerols and in glycolysis were enriched. For 90 AW-box sequences associated with these target genes, binding affinity to heterologously expressed Arabidopsis thaliana WRI1 protein was determined using Microscale Thermophoresis. Sites with low dissociation constants are preferentially located close to the transcriptional start site and are highly conserved between the 12 Brassicaceae species. Most of the associated genes were found to be co-expressed with WRI1 during seed development. When 46 automatically and manually curated genes containing conserved AW-sites with high binding affinity are mapped to central metabolism, a conserved regulatory blueprint emerges that infers concerted control of contiguous pathway sections in fatty acid biosynthesis and glycolysis. Among unexpectedly identified putative targets of WRI1 are plastidic fructokinase, phosphoglucose isomerase and several transcription factors. One sentence summaryA combined comparative genomics and in-vitro DNA binding assay approach was used to identify conserved binding sites for the WRINKLED1 transcription factor in central metabolism and lipid biosynthesis.

plant biology↗

bioRxiv2019

BIOTIN ATTACHMENT DOMAIN-CONTAINING proteins, inhibitors of ACCase, are regulated by WRINKLED1

WRINKLED1 (WRI1) is a transcriptional activator that binds to AW boxes in the promoters of many genes from central metabolism and FA synthesis, resulting in their transcription. BIOTIN ATTACHMENT DOMAIN-CONTAINING (BADC) proteins are homologs of BIOTIN CARBOXYL CARRIER PROTEIN (BCCP) that lack a biotin-attachment domain and are therefore inactive. In the presence of excess FA, BADC1 and BADC3 are primarily responsible for the observed long-term irreversible inhibition of ACETYL-COA CARBOXYLASE (ACCase), and consequently FA synthesis. Purified WRI1 bound with high affinity (Kds in the low nanomolar range) to canonical AW-boxes from the promoters of all three BADC genes. Consistent with this observation, the expression of BADC1, BADC2 and BADC3 genes and BADC1 protein levels were reduced in wri1-1 relative to wild type (WT), and BADCs gene expression and BADC1 protein levels also were elevated upon WRI1 overexpression. The double mutant badc1badc2 phenocopied wri1-1 with respect to both reduction in root length, and elevation of indole-3-acetic acid-Asp (IAA-Asp) levels relative to WT. Overexpression of BADC1 in wri1-1 decreased its IAA-Asp and partially rescued its short-root phenotype demonstrating a role for BADCs in seedling establishment. That WRI1 positively regulates genes encoding both FA synthesis and BADCs i.e., conditional inhibitors of FA synthesis, represents a coordinated mechanism to achieve lipid homeostasis in which plants couple the transcription their FA synthetic capacity with their capacity to biochemically downregulate it.\n\nOne sentence summaryWRI1 regulates genes encoding both fatty acid synthesis and inhibitors of FA synthesis (BADCs), creating a lipid homeostatic mechanism in which the transcription of FA synthetic capacity is coordinated with the capacity to biochemically downregulate FA synthesis.

plant biology↗